Assessment of wall shear stress in the common carotid artery of healthy subjects using 3.0-tesla magnetic resonance

Abstract

BACKGROUND: Wall shear stress (WSS) has been proven to play a critical role in the formation and development of atherosclerotic plaques. Measurement of WSS in vivo is significant for the clinical assessment of atherosclerosis. PURPOSE: To assess the magnitude and distribution of local WSS in the common carotid artery (CCA) in vivo using 3.0T magnetic resonance (MR). MATERIAL AND METHODS: The common carotid artery of eight healthy volunteers was studied using a cine phase-contrast MR sequence. A three-dimensional paraboloid model was applied to fit the velocity profiles, and the WSS values were calculated. The cross-sectional area, average flow velocity, maximum velocity, and flow rate were also obtained. RESULTS: Mean WSS was 0.850 +/- 0.195 (range 0.132-3.464) N/m(2) for the common carotid arteries; the spatial and temporal distribution and change of WSS were displayed. During a cardiac cycle, the mean velocity was 22.8 +/- 3.5 (16.9-28.3) cm/s, blood flow rate 8.03+/-1.45 (5.73-10.72) ml/s, and luminal vessel area 34.94+/-7.06 (24.25-49.01) mm(2). CONCLUSION: Local WSS values in CCAs can be measured using 3.0T MR imaging combined with image-processing techniques. Intersubject variations were found in the distribution and magnitude of wall shear stress as well as in the flow profile pattern in CCAs, which may be caused by different vessel morphologies.